Automatic circuit-breaking electric switch



NVENmR.

A TTDRNEY.

Ll X100 Aug. 26, 1941. '.1'. A. KAMMERDINER AUTOMATIC CIRCUIT-BREAKING ELECTRIC SWITCH Filed March ll. 1939 Patented Aug. 26, 1941 AUTOIJIATIC CIRCUIT-BREAKING ELECTRIC SWITCH James A. Kammerdiner, Los Angeles, Calif.

Application March 11, 1939, Serial No. 261,217

1 Claim.

This invention relates to electric switches, and more particularly to an automatic circuit-breaking electric switch.

The general object of the invention is to provide an electric switch to be connected in an electric circuit, which, when subjected to a shock, such as an earthquake or the vibration caused by the falling yof a building, will automatically open and break the circuit.

Other objects and advantages will appear hereinafter.

The invention is illustrated in the annexed drawing, which forms a part of this specification and in which:

Fig. 1 is a side elevation of my automatic electric switch, with the detachable side plate of its casing partly broken away to show the parts within said casing, and showing my switch in its normal closed position.

Fig. 2 is a transverse vertical section oi my switch taken on line 2-2 of Fig. 1.

Fig. 3 is a View like Fig. 2, except that the switch is shown in its open position.

Fig. 4 is a side elevation of a modification of my invention, with the detachable side plate; its casing partly broken away to show the parts within said casing, and showing my switch in its normal closed position.

Fig. 5 is a transverse vertical section taken on line 5 5 of Fig. 4.

Fig. `6 is a horizontal section taken on line E--G of Fig. 4.

Fig. 7 is a vertical longitudinal section of another modication of my invention.

Fig. 8 is a side view of a switch embodying another modication of my invention.

Fig. 9 is a front view of Fig. 8 with the cover of the switch box removed.

Referring more particularly to the drawing, in which corresponding parts are designated by the same reference numerals in all of the views, I designates a switch casing, 2 and 3 stationary switch contacts and 4 a metal ball forming a movable switch contact. The stationary contact 2 is formed of a piece of sheet metal bent downwardly af-t right angles into a connecting member 5, and said contact extends horizontally and rests upon the top of a block of insulation 6 with its connecting member 5 against t'he right side of said block (Fig. 1). Said contact 2 is secured on the block 6 by a terminal screw I which extends through the connecting member 5 into said block in threaded engagement with said connecting member and said block. The block 6 is secured in position in the casing I by screws 8,

which extend through the rear wall 9 of said casing into and in threaded engagement with said block. In the upper surface of the contact 2 is formed a seat I0, with a slight depression, in which the ball 4 rests with the right side thereof in contact with the end of the stationary contact 3, when the switch is closed, as shown in Fig. 1. The remote or left end II (Fig. 1) of the contact 2 is bent downward, so that the ball 4 may readily roll out of its seat I0 down over said bent end and off said contact, to open the switch, when it is subjected to a shock such as an earthquake. The stationary contact 3 is formed on the end of `a terminal screw I2 which extends through and is threaded in Aa block of insulation I3 secured in th-e upperfpart of the casing I by screws I4 extending through the rear wall 9 of said casing into and in threaded engagement with said block.

The casing -I comprises the rear wall 9, bottorn wall I5, top wall I-6 side walls I'I and I8 and detachable front wall I9 which is secured to the front of said casing by screws `2l] extending through said front wall, at the corners thereof, into threaded openings 2I inthe corners of said casing. Sight openings 22 and 23 are provided in the rear wall 9 and the front wall I9 respectively of the casing I, through which openings the ball 4 may be seen when it is upon its seat I0 closing the switch. Said sight openings 22 and 23 are closed by transparent panels 24.

An electrical conduit 25 extends through the side Wall I8 of the casing l into the lower part of said casing and is secured in said wall by clamp nuts 26 and 2l threaded on said conduit which nuts engage the inner and outer sides of said wall. Branch mains 28 and 29 extend through said conduit 25 into the lower part of the casing I and are connected to the terminal screws 28 and 29 respectively.

The operation, uses and advantages of vmy invention are as follows:

My switch is closed, when the ball 4 rests upon the seat IU and against the contact 3, and electric current passes through the circuit in which the branch mains 28 and 29 and my switch are included, the current passing through branch main 28, terminal screw 1, connecting member 5, contact 2, ball 4, contact 3, terminal screw I2 and branch main 29.

In the event of an earthquake or the falling of a building, in which a circuit receives its current from the branch main 28 connected to my switch, which is located where the branch main 29 leads from my switch into the building, the shock or vibration produced by said earthquake or falling building will cause the ball 4 to roll out of its seat I away from contact 3, over the downwardly bent end of the stationary contact 2 and off said contact into the bottom of the casing I, whereby my switch will be opened and the circuit, including the mains 28 and 29 and my switch, will be broken between the switch contacts 2 and 3, so the remen, workmen or anyone coming into contact with any of the wires of said circuit in the ruins of the earthquake or the wreckage of the fallen building will not receive 4an electric shock and be severely burnt or electrocuted by such shock, and any danger of fire by grounding or short circuiting of broken wires of the circuit will be prevented.

When it is desired to reset the switch in closed position the front plate I9 is removed from the casing I upon removing the screws 28; the ball 4 is then picked up and placed back upon its seat I0 against the contact 3; and the front plate I3 is then secured back on the front of the casing by the screws 28.

The modification of my switch shown in Figs. 4, and 6 comprises a pair of spring contacts 3U and 3|, a pair of link contacts 32 and 33, a ball 34 and a seat 35 upon which said ball rests when the switch is open. The spring contacts 38 and 3| are secured by screws 36 and 31 respectively to insulation blocks 38 and 39, which blocks are secured to the side walls of a casing 48 by screws 4|. The link contacts 32 and 33 are pivoted together at their inner ends by a pivot 42 and are pivoted at their outer ends, by pivots 43 and 44, to the lower ends of suspension links 45 and 46 respectively, the upper ends of which links are pivoted on pins 41 and 48 respectively secured to the rear wall 48 of the casing 48. The ball 34 is confined within a guide tube 5D mounted in the casing 40, which tube is bent in the form of a vertical member 5|, and a horizontal member 52 at the upper end of said vertical member, the ball seat 35 being formed in the lower wall of said horizontal member, and said vertical member being located directly over the inner ends of the link contacts 32 and 33, so that said link contacts are held against the lower end of said vertical tubular member by the engagement of the spring contacts 30 and 3| with the outer ends v and adjusting the ball 34 to its seat 35 so that i said ball will roll out of its seat when subjected to sufcient shock or vibration. A conduit 55 extends through the bottom wall 56 of the casing 40 into the bottom of said casing, and leads 51 and 58 of an electric circuit extend through said conduit into the lower part of said casing to the spring contacts 30 and 3| and are secured to said contacts by the terminal screws 36 and 31 respectively. The front of the casing 40 is closed by a detachable front wall 59 which is secured to said casing by screws 59' which extend through said front wall at the corners thereof into threaded openings 40' in the corners of said casing.

The operation of this modification of my invention is as follows:

The ball 34 rests upon the seat 35 and the spring contacts 38 and 3| engage the outer ends of the link contacts 32 and 33 respectively and hold said contacts with their pivoted inner ends raised and their upper edges against the lower end of the vertical tubular member 5| of the guide tube 5D, when the switch is in its closed position, in which position of the switch electric current passes through lead 51, spring contact 38, link contacts 32 and 33, spring contact 3| and lead 58 and the rest of the circuit in which the switch and the leads 51 and 58 are included.

When the switch is subjected to suicient shock the ball 34 rolls out of its seat 35 and out of the horizontal member 52 of the guide tube 50, and drops down through the Vertical member 5| of said guide tube upon the inner ends of the link contacts 32 and 33, depressing said ends of said contacts, which contacts are swung down on their pivots 43 and 44 at their outer ends, and said outer ends of said link contacts are drawn inwardly out of engagement with the spring contacts 3D and 3| respectively, the links 45 and 46 swinging inwardly at their lower ends on their pivots 41 and 48 to permit the inner ends of said link contacts 32 and 33 to be withdrawn out of contact with the spring contacts 3i) and 3| which opens the switch and breaks the circuit in which the leads 51 and 58 are included.

To reset the switch the front plate 51 is removed from the casing 48 upon removing the screws 58; the ball 34 is picked up and inserted through an opening 52 in the front side of the guide tube member 52 and placed upon its seat 35 in said member; the inner ends oi the link contacts 32 and 33 are swung up until the outer ends of said link contacts engage the spring contacts 3l] and 3| respectively and the upper edges of said link contacts engage the lower end of the guide tube member 5|; and the front plate 59 is then secured back on the front of the casing 48 by the screws 59.

The modiiication of my invention shown in Fig. 7 comprises a casing 68, screw terminals 6| and 62 in said casing, a small wire 63 drawn taut between and connected to said terminals, a vertical guide tube 64 connected at its lower end to the top wall 65 of said casing 6U and leading into the upper part of said casing, a ball 66 and a seat 61 in the lower wall of a horizontal extension 68 of the upper end of said guide tube. A

horizontal plate 69 is mounted in the casing 68 below the wire 63 and a short distance above the bottom wall 10 of said casing. A conduit 1| extends through the bottom wall 16 into the lower part of the casing below the plate 69, and leads 12 and 13 of an electric circuit extend through said conduit into the lower part of said casing under said plate to the screw terminals 6| and 62 respectively and are connected to said terminals. The front of the casing 60 is closed by a detachable front wall 14, secured to the casing by screws 15 which extend through said wall at the corners thereof into threaded openings 16 in the corners of said casing. The outer end of the member 63, extending from the upper end of the guide tube 64, is closed by a screw plug 11, which engages an internal thread 18 in said outer end of said tubular member. An adjusting screw 19 extends through the plug -11 in threaded engagement therewith for engaging the ball 66 and adjusting it properly to its seat 61 so that said ball will roll out of said seat when subjected to the required shock or vibration.

The operation of this modification of my invention is as follows:

This switch is closed when the wire 63 extends from terminal 6| to terminal 62 and the ball 66 rests upon its seat 61, as shown in Fig. 7, and electric current passes though lead 12, terminal 6|, wire 63, terminal 62 and lead 13, and through the rest of the circuit in which said leads 12 and 13 are included.

When the switch is subjected to sullicient shock or vibration the ball 66 rolls out of its seat 61 and out of the horizontal tubular member 68 and drops down through the Vertical guide tube 64 upon the wire 63 and breaks said wire, which opens the switch and breaks the circuit in which the switch and the leads 12 and 13 are included. After breaking the wire 63 the ball 66 drops upon the plate 69, as shown in dotted lines in Fig. 7.

When it is desired to reset the switch in closed position, the front plate 14 is rst removed from the casing 66, upon removal of the screws 15, and the ball 66 is removed from the casing; the broken wire 63 is then removed from the terminals 6| and 62 and the casing 66, and a new wire 63 is connected to said terminals; the front plate 14 is then secured on the front of the casing 66 by the screws 15; the plug 11 is then unscrewed from the outer end of the tubular member 68 and the ball 66 is inserted through said open outer end into said tubular member and placed upon its seat 61; and the plug 11 is then screwed back into the outer end of the tubular member 68.

I do not limit my invention to the exact form and construction herein disclosed since various changes may be made therein without departing from the spirit of the invention.

In the modication shown in Figs. 8 and 9 my invention is applied to a conventional knife switch 66 and includes a ball 8|, seat 82, a switch lever connecting arm 83 and a chain 84 connected to said ball and to the outer end of said connecting arm. The connecting arm 83 is formed with a sleeve 85 which detachably lits on the upper end of the actuating arm 86 of the switch lever 81 so that said connecting arm extends rearwardly from and at right angles to said switch lever actuating arm. The switch lever 81 is pivoted at 88 and 89 in the side walls of switch box 96 with its actuating arm 86 outside and at one side of said switch box. The switch lever 81 extends through the fork arm 9| secured to the cross bar 92 which is connected at its ends to the switch blades 93 and 94. Said switch blades are pivoted at their lower ends to terminals and 96, mounted on the insulation base block 91, so that when the switch lever actuating arm 86 is in a vertical upstanding position the upper ends of the blades 93 and 94 extend into the spring clip contacts 98 and 99 respectively, which terminals are also mounted on the insulation base block 91. Mains |66 and |6| are connected to the terminals 95 and 96, respectively, and leads |62 and |63 of a circuit are connected, respectively, to the contacts 98 and 99. The seat 82 is formed on a bracket |64 secured to the outside of one of the side walls of the switch box 90.

The operation of this form of my invention is as follows:

When the ball 8| is subjected to a shock, such as an earthquake or the falling of a building, the ball rolls olf its seatand the weight of the falling ball, suddenly applied through chain 84 to the outer end of the connecting arm 83, swings the switch lever 81, through its actuating arm 86, rearwardly, which lever, through fork arm 9| and cross bar 92, swings the switch blades 93 and 94 rearwardly out of contact with the clip contacts 96 and 99 and opens the switch which breaks the circuit supplied by the leads |62 and |63.

The ball 8| may be readily replaced upon its seat 82 when it is desired to close the switch.

I claim:

An automatic circuit-breaking switch comprising a casing, a pair of spring contacts mounted in said casing, a pair of link contacts pivoted together at their inner ends, a pair of suspension links pivoted at their upper ends to said casing and at their lower ends to the outer ends of said link contacts respectively, so that when the inner connected ends of said link contacts are raised their outer ends .are forced outwardly against said spring contacts and the switch is closed thereby, means for limiting the upward movement of said link contacts, a seat mounted in said casing and a ball to be seated on said seat when the switch is closed and to be shaken oil" said seat by shock to drop upon and depress the inner ends of said link contacts to withdraw the outer ends of said link contacts from said spring contacts and open the switch.

JAMES A. KAMMERDINER. 

